CVE-2026-64137smb: client: require net admin for CIFS SWN netlink
- 7.8HighCVSS base score
- 0.13%Exploitation in 30 daysEPSS · top 97% of all CVEs
- NoKnown exploitednot in CISA's KEV catalog
- NonePublic exploitsnone known yet
Description
In the Linux kernel, the following vulnerability has been resolved: smb: client: require net admin for CIFS SWN netlink CIFS_GENL_CMD_SWN_NOTIFY is the userspace witness-notify command. The intended sender is the cifs.witness helper, but the generic-netlink operation currently has no capability flag, so any local process can send RESOURCE_CHANGE or CLIENT_MOVE notifications to the in-kernel witness handler. The same family exposes CIFS_GENL_MCGRP_SWN without multicast-group capability flags. Register messages sent to that group include the witness registration id and, for NTLM-authenticated mounts, the username, domain, and password attributes copied from the CIFS session. An unprivileged local process should not be able to join that group and receive those messages. Require CAP_NET_ADMIN for incoming SWN_NOTIFY commands with GENL_ADMIN_PERM, and require CAP_NET_ADMIN over the network namespace for joining the SWN multicast group with GENL_MCAST_CAP_NET_ADMIN. The cifs.witness service runs with the privileges needed for both operations.
Timeline
ID reserved
By Linux
Published
- 17 days later
· 17 days later
Record updated
Changes after publication (a new score, a public exploit, EPSS crossing 1, 10 or 50 %, leaving KEV) are kept since November 2026; earlier ones are not known.
Scores
| Scored by | CVSS | Score | Vector |
|---|---|---|---|
| LinuxCNA (assigner) | 3.1 | High7.8 | CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H |
| NVDNVD · Analyzed | 3.1 | High7.8 | CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H |
- EPSS (exploitation in 30 days)
- 0.13% · top 97% of all CVEs (15 Nov 2026)
The list uses the assigner's score when there is one, then CISA's, then NVD's: High 7.8.
Affected products
- affected fed979a7e082bd9f25f9002c3c4f8740dacd0bc8 – < 9cf7eb8919344932f909b2fac76296f7656fda8d
- affected fed979a7e082bd9f25f9002c3c4f8740dacd0bc8 – < 9919021a3b7974ae66a5f9915e3a48c10cfd409b
- affected fed979a7e082bd9f25f9002c3c4f8740dacd0bc8 – < 969bc6370334a5b4720c5470783295d6484bbc95
- affected fed979a7e082bd9f25f9002c3c4f8740dacd0bc8 – < a3238b09c58f323e40743ce174cd0ab81b5c09ed
- affected fed979a7e082bd9f25f9002c3c4f8740dacd0bc8 – < a8d17d22db591099519a89f14dd24810daba74c3
- affected fed979a7e082bd9f25f9002c3c4f8740dacd0bc8 – < c2397b93fbb6f44a788fff30f99be2c20cc5e50f
- affected fed979a7e082bd9f25f9002c3c4f8740dacd0bc8 – < d1ebfce2c1d161186a82e77590bf7da2ea1bce91
- affected 5.11
- unaffected < 5.11
- unaffected 5.15.210 – ≤ 5.15.*
- unaffected 6.1.176 – ≤ 6.1.*
- unaffected 6.6.143 – ≤ 6.6.*
- unaffected 6.12.92 – ≤ 6.12.*
- unaffected 6.18.34 – ≤ 6.18.*
- unaffected 7.0.11 – ≤ 7.0.*
- unaffected 7.1 – ≤ *
References
References7
- https://git.kernel.org/stable/c/9cf7eb8919344932f909b2fac76296f7656fda8d (opens in a new tab)
- https://git.kernel.org/stable/c/9919021a3b7974ae66a5f9915e3a48c10cfd409b (opens in a new tab)
- https://git.kernel.org/stable/c/969bc6370334a5b4720c5470783295d6484bbc95 (opens in a new tab)
- https://git.kernel.org/stable/c/a3238b09c58f323e40743ce174cd0ab81b5c09ed (opens in a new tab)
- https://git.kernel.org/stable/c/a8d17d22db591099519a89f14dd24810daba74c3 (opens in a new tab)
- https://git.kernel.org/stable/c/c2397b93fbb6f44a788fff30f99be2c20cc5e50f (opens in a new tab)
- https://git.kernel.org/stable/c/d1ebfce2c1d161186a82e77590bf7da2ea1bce91 (opens in a new tab)
Sources
The same CVE in the primary databases and aggregators, to check against.
- CVE.org record (opens in a new tab)
- CVE List JSON (GitHub) (opens in a new tab)
- NVD (opens in a new tab)
- FIRST EPSS (opens in a new tab)
- EUVD EUVD-2026-45822 (opens in a new tab)
- OSV.dev (opens in a new tab)
- GitHub Advisories (opens in a new tab)
- CIRCL Vulnerability-Lookup (opens in a new tab)
Badge for a README or a ticket
[](https://cveledger.app/cve/CVE-2026-64137)Record last updated .